WAR have better movility with Onslaught since it have lower recast, its on demand whenever he wants and have better range that plunge 20yalms vs 15 yalms and anti-knockback on holmgang and inner release with obviously you will not use those skills for that but if sincs with a mechanic is another adventage that WAR enjoy.
so tell me how WAR is the bottom on mitigation when it have:
-rampart 20s 90 recast
-vengeance 15s 120 recast
-thrill of battle 20s 120 recast (its not mitigation but its efective HP)
-raw intuition 20s 90 recast only physical
-inner beast 6s on demand as longer you have gaude
-holmgang 6s 180 recast
vs
PLD:
-rampart 20s, 90s recast
-sentinel 10s, 180s recast
-sheltron 10s, 5s recast
-bulwark it's not effective against TB
-hallowed ground 10s, 420s recast
DRK:
-rampart 20s, 90s recast
-shadow wall 10s, 120s recast
-the blackest night 7s, 15s recast
-dark mind 10s, 60s recast only magic
-living dead 10s precast, walking dead 10s, 300 recast
so WAR have 4-5 (depending of the stance) efective CDs and 5-6 on physical encounters vs 4 efective cds on PLD 1 of then being usable 1-2 per fight as much and 4 CD'S (5 against magical TB) on DRK and DRKs want to avoid living dead as much as posible so it leave then with 3-4 most of the time, so WAR wins.
on defiance WAR mitigate much more that PLD and DRK, not only they have more CDs with longer duration and shorted recast but his 25% extra HP represents the same efective HP that grit/shield 20% mitigation plus they will have stronger shields from AST and SCH, being able to stack several amounts of CDs with inner beast vs the 1 DRK and PLD have to spend with sheltron/TBN having way more overall mitigation and on top of that being able to heal part of the damage with equilibirum every single TB for free for not mention the constant 6s of inner beast mitigation and selfhealing WAR is enjoying constantly when is on defiance outside of TB.
so while WAR is a bit limited on deliverance (not really) they overall mitigation and self-healing surpass by far the other 2 in defiance and they don't depend more of others that the other tanks.